Device for limiting the field of fire in elevation on an automatic firearm

Abstract

A device for limiting the field of fire in elevation on an automatic firearm prevents the weapon from being fired when it is in certain, unsuitable positions. The weapon may not then be operated by either the electrical or the mechanical trigger. The operation of an electrical switch when the weapon is swung beyond a given angle of elevation to disconnect the electrical trigger is known. According to the invention, when the weapon is swung beyond the given angle of elevation known firing pin locks are mechanically actuated, which prevents the advancing breechblock which pushes the cartridge into the gun barrel from piercing the cartridge. A cam roller or follower is preferably arranged on the weapon and which strikes a fixed lifting flank or cam when the weapon is swung at a given angle of elevation.

We claim: 
     
       1. An automatic firearm field of fire limiting device for a firearm having an electrical trigger, a mechanical trigger and a movable breechblock movable to perform an advance movement and a movement into a rearmost position, comprising: switch means for disconnecting said electrical trigger when the switch means is actuated;   firing pin lock means for preventing advance movement of said breechblock and rendering ineffectual said mechanical trigger;   elevation angle detection means detecting when the firearm has exceeded a predetermined angle of elevation and operative to activate said switch means and said firing pin lock means to disconnect the electrical trigger and inactivate said mechanical trigger;   cam means for operating the switch means and the firing pin lock means;   a lifting flank adapted to be fixedly located at a firing position for the firearm, so that said cam means contacts said lifting flank and is raised by said lifting flank when the firearm is elevated;   linkage means linking said cam means to said firing pin lock means to activate said firing pin lock means when the firearm exceeds a predeterminate angle of elevation;   said linkage means comprising: fixedly mounted bracket means;   spring-loaded control means mounted in said fixedly mounted bracket means;   cable means connecting said cam means and said spring-loaded control means such that movement of said cam means on said lifting flank during elevation of the firearm displaces said spring-loaded control means against the spring-loading of said spring-loaded control means;   follower means mounted for recoil with the firearm and contacting said spring-loaded control means and maintaining contact with said spring-loaded control means during recoil of the firearm; and   said follower means displacing said firing pin lock means upon displacement of said spring-loaded control means.     
     
     
       2. The automatic firearm field of fire limiting device as defined in claim 1, wherein: said follower means comprising bell crank means;   spring-loaded rod means urged against said bell crank means for displacement of said spring-loaded rod means by said bell crank means upon displacement of said spring-loaded control means; and   lifting flank means mounted on said spring-loaded rod means for lifting said firing pin lock means upon displacement of said spring-loaded rod means in order to activate said firing pin lock means.   
     
     
       3. The automatic firearm field of fire limiting device as defined in claim 1, further including: electromagnet means operated by said switch means;   pawl means for engaging said breechblock of the firearm in order to hold said breechblock in the rearmost position thereof;   said pawl means being activatable by said electromagnet means in order to release said breechblock from retention in said rearmost position; and   said switch means being operable by said cam means to de-energize said electromagnet means when said firearm exceeds the predetermined angle of elevation.